This is the normal RM1 which can be easily found circulated in the market. Signed by Gabenor Bank Negara, Tan Sri Dato' Seri Dr Zeti Akhtar Aziz.
This one is claimed to be unissued, but somehow the Central Bank's mistake to release it into the circulation. I can't be quite sure about this and still looking for valid confirmation. This piece was signed by Tan Sri Ali Abul Hassan.
Ok, this is one piece somebody's trying to sell on the eBay. Look at the price, and mind you the quality of the note is not more than Very Good (VG-grade).
Bank Negara Malaysia is reintroducing the new RM1 note, the sixth denomination issued in the new design Malaysian currency notes series (3rd series). The new RM1 bears the signature of the present Governor, Tan Sri Dato' Sri Dr. Zeti Akhtar Aziz, who assumed office on 1 May 2000. The new RM1 note printed earlier bears the signature of the Immediate Past Governor Tan Sri Dato' Seri Ali Abul Hassan bin Sulaiman. The new RM 1 note will incorporate the latest security features to deter counterfeiting.
The theme of the new series, "Wawasan 2020" reflects Malaysia's economic development and accomplishment towards achieving the status of a fully developed country. The main focus reflected in the background motif is the tourism sector. This is depicted with an illustration of a Malaysian kite, the beach, Mount Kinabalu and the pinnacles of Gunung Api located in Mulu National Park. This motif also reflects some off the popular tourist destinations in the country. As with the other denominations of the same series, the new RM1 note will also bear RM as the currency symbol for the Malaysian Ringgit.
The one signed by Tan Sri Ali Abul Hassan only has the prefix started by CR. The market price would be around RM750 for uncirculated, while circulated (in the conditions of good to very good) can take the price around RM300 to RM450.
So, the next time you receive RM1, do check the signature! Who knows you might have chance to make some profit of 350% from the face value.
The one I bought cost me RM350.00
Just for knowledge sharing.
Update 2012/July/14
The information has been updated at http://www.exonumi.com/?page=publish&id=1.25.BN.a5604 with more newly covered information.